Improvement in processes for making japanned leather



ters Patent.

UNITED STATES PATENT OFFICE.

HIRAM L. HALL, OF BEVERLY, MASSACHUSETTS, ASSIGNOR TO JAMES I i O.STIMPSON.

IMPROVEMENT IN PROCESSES FOR MAKING JAPANNED LEATHER.

To all whom it may concern:

Be it known that I, HIRAM L. HALL, ofBe'verly, in the county of Essexand State of Massachusetts, have discovered certain new and usefulImprovements in the Process of Manufacturing Japanned Leather, by whichimprovements an article of manufacture much superior to anythingheretofore produced is secured; and I do hereby "declare that thefollowing description is a full and exact specification of the saidprocess, wherein I have set forth the distinguishing features of my saidimprovements, together with such parts as 1 claim and desire to havesecured to me by Let- In the preparation of japanned leather by any ofthe'modes hitherto practiced it has been the custom to apply the varnishto the leather as it comes from the hands of the tanner, and thensubject the leather and the several coats of varnish,as they aresuccessively applied,to as high a. degree of heat as they will hear. Theheat, applied without any previous preparation of the leather save thatof tanning,has had the effect to rot or injuriously affect the fiber ofthe leather, and in order to measurably guard against the rotting effectthe degree of heat applied has almost always been kept within 160Fahrenheit, which does not sufficiently indurate the varnish to make itstand every variety of climate.

My improvements have'mainly for their objcct the preparation of theleather after it has been tanned, so thatitean be toughened to endure amuch greater degree of heat than 160 in the process of japanning, eventhat of 230 and upward, which enables the varnish applied to endureevery possible climate, while the fiber-of the leather is not injuriously qualified. I effect this desideratum of protecting the fiberofthe leather from the effects of the heat during the process ofmanufacture by applying to the leather a composition composed of thefollowing ingredients: two ounces sulphur, freed from its acid, or, as asubstitute for sulphur, two ounces of sulphate of potash; one-halt ouncealum 5 one-halfounce borax. These substances are dissolved in one quartof water.

The leather is then thoroughly saturated with theliquid thus obtained,by immersion or otherwiseif by immersion, to remain in the liquid fromone to two hours, the time varying with the thickness of the leather tohe saturated. The leather is then dried in any convenient manner. Themethod of drying which I have found the most successful is to place theleather in a revolvin g cylinder constructed of fine wire meshes. Therevolutions of this cylinder and the centrifugal force obtained therebydrive out the'water, work over the leather, and have the same effect tomake the leather pliable as would be obtained in passing it throughacommon boarding-machine, such asis used by manufacturers of japannedleather. When the leather is nearly dry it is stretched, as in the usualprocess of manufacturing such leather, and is then ready to receive thevarnishes which are usually applied, and which do not requiredescription, as they are well known to manufacturers of patent-leather.After the leather has been sufficiently coated it is placed in an ovenstretched upon suitable frames or suspended in the same. This oven isarranged so that the heat can be regulated at pleasure, and should begradually heated from a low degree to a temperature of 230 or 250Fahrenheit. The leather is kept in the oven from six to ten hours, untilthe composition is completely matured and the surface perfectly dry.

In the above-described composition for preparing the fiber of theleather the borax may be dispensed with, as it is not absolutelynecessary for producing the effect, but as it prevents therecrystallization of the sulphur and alum I have found it mostadvantageous to use it.

The ingredients of the composition for protecti'ng the fiber of theleather from the effects of the heat are such as-we have found to be thebest adapted to the purpose; but any substances which have the samechemical properties as those above stated may be substituted withoutvarying the essential principles of my discovery.

Having thus described my improvements, I shall state my claims asfollows:

What I claim as my discovery 0r invention, the varnish coatings thereon,to a high degree and desire to have secured to me by Letters of heat,whereby the surface of the leather is Patent, isso matured as not to beaffected by any tem- The improvementin the process of manufacperature orchange of climate.

turing patent or japanned leather which con- HIRAM L. HALL.

sists in applying to the'leather the composition Witnesses:

hereinabove described, (prepared either with SAMUEL ADAMS,

or without borax,) and then sub1nittingit,'ivitl1 HENRY B. CLARK.

